Home / Standards / MT 20-1990 MT 20-1990 Active 立井多绳提煤箕斗 Standard Type MT20 ICS N/A CCS N/A Status Active Issue Date 1990-10-26 Implementation 1990-11-01 Centralized Committee 国家矿山安全监察局 Issuing Authority 国家矿山安全监察局